Two and a half year old waking for 1-2 hours per night

my ds who is three in May has been sleeping really badly the past month. For at least two-three nights a week he is up for at least an hour a night mostly longer, wants to get in our bed and all sorts of high jinks.

He still naps for two hours in the day and I was wondering if this is the problem or could it be a developmental thing?

i am pregnant and we are immigrating in a month so we are stressed and really need our rest!